feat(chat/notif): single hover action-pill; sender DP in desktop+mobile notifications

- Message actions (reply/react/edit/delete) consolidated into ONE hover pill anchored to the
  bubble's top-right, overlapping it so on short messages the icons no longer float off into
  empty space and vanish before you can click.
- Desktop toast + mobile(FCM)/web-background push now show the sender's real DP:
  * renderer passes the DP URL through; desktop shell downloads it for the toast icon
    (canvas-drawing an external DP tainted it → initials). Desktop bumped to 0.1.4.
  * DM push payload carries icon=sender avatar; sw.js already uses it (web background),
    sendFcm sets notification.image (Android).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

desktop/package.json

@@ -1,6 +1,6 @@
 {
   "name": "biz-connect-desktop",
-  "version": "0.1.3",
+  "version": "0.1.4",
   "description": "Biz Connect technician desktop client — loads the Connect web UI with native screen capture",
   "author": {
     "name": "BizGaze",